Sizing composition.



ILLIAM HOSKINS, OF LA GRANGE, ILLINOIS.

SIZING COMPOSITION.

No Drawing.

Specification of Letters Patent. Application filed Iareh 19, 1909.Serial No. 484,539.

Patented Nov. 16, 1909.

To all whom it may concern:

Be it known that I, WILLIAM Hosxms, a citizen of the United States,residing at La Grange, in the county of Cook and State of Illinois, haveinvented a new and useful Improvement in Sizing Compositions, of whichthe following is a specification. 1

My object is to provide, as a new article of manufacture, paper-sizingcompounded in such a way'as t-o'render its use by paper manufacturersparticularly convenient and economical andzenable them, furthermore, toeffect the results desired in the ultimate paper product with greateruniformity and less trouble than hitherto.

In the rosin-soap, called rosin-size,'is added to the pulp during thebeating operationand thoroughly mixed therewith. Alum, or aluminumsulfate, is then added to react with the rosin-soap and decompose andset free rosin and form aluminum resinate. Authorities differ as to theprecise reactions that take place, but the effect upon the pulp is tocause a certain amount of the rosin, or aluminum resinate, to adhere tothe particles of fiber, so that when the sheet of paper is made it isless pervious to Water than would be the case without the sizing. Therosin-soap is ordinarily produced, at the paper mill, by heating therosin in contact with a solution of soda ash, or caustic soda, by meansof steam. To produce a good quality of sizing requires time, skill andcare, and to effect the best results a knowledge of the purity of theconstituents is necessary for the purpose of arriving at the correctproportions to be used and to avoid waste. Different lots of size willvary materially in the proportion of water present, and this leads touncertaintyas to the quantity of size to be added to the pulp, and alsoto the alum required, and this uncertainty tends toward inferiority andlack of uniformity in the final prodnet and also to a waste ofmaterial.- To

avoid the above difiiculties I provide a uniform sizing mixture socompounded as to produce the desired results in an unvarying manner.

In carrying out my invention I proceed as follows: T 0, say, 100 poundsof a certain lot of rosin I add approximately 11% pounds of causticsoda, the precise amount necessary for any given lot of rosin beingaccuratel determined by chemical test. 'I also add su ficient water,say, 25 per cent. of the weight process of manufacturing paper,

of. the alkali, to cause'ready saponification. These ingredients arethoroughly mixed together and heated, preferablv in a steamjacketedchamber, until saponification is complete. .'I he mixture is thenallowed to cool, becoming a brittle mass of rosin-soap, easilypulverized, and after its pulverization I mix with it, say, pounds of aninert pulverulent material, such as china clay, or talc, to prevent theparticles of the rosin-soap from adhering ,toeach other and forminglumps, as would occur if moisture wereabsorbed thereby, or if itstemperature were raised. To the dry pulverulent mixture thus produced, Iprefer to add, say, 16.6 pounds of a dry and powderedrosin-soap-decomposing reagent, such, for example, as aluminum. sulfate,incorporating it thoroughly with the other particles. I find that it isdesirable to use as such reagent dehydrated alum -(alum which has beendeprived of its water of crystallization), as this dissolves in watermuch more slowly, even in a powdered state, than does the powderedrosin-soap, thus allowing time for the thorough mixing of the soap withthe pulp before it is acted upon to any extent by the alum.

Dry rosin-soap when in lump form dis-. solvesvery slowlyand when itisemployed the practice is to liquefy it by heating in contact withwater before adding it to pulp in order to mix therewith quickly andproperly. If the rosin-soap is pulverized, however, and kept fromagglomerating into lumps, as b having incorporated with it aninertmaterlal, such as powdered china clay, it dissolves quickly. Chinaclay is frequently used as a constituent part of paper pulp, and therelatively small quantity of the same, or equivalent inert material,necessary for'keeping the rosin-soap in a pulverized condition, wouldbeof no disadvantage to the paper. Pulverized rosin-soa mixed with asuitable quantity of pulverize inert material may be provided wlthoutthe decomposing reagent to paper manufacturers, who, after mixing 1twith pulp, could add thereto the desired quantity of alum or equivalentmaterial. I believe, however, that,'as a rule, a more uniform anddesirable product would be obtained by paper manufacturers if thecompound of pulverized rosin-soap (of known chemical composition) andinert material, has mixed therewith, in the first instance, only thenecessary and most desirable quantity of soap-decom- I suitableproportions,

posing reagent, also of known analysis, thereby making it necessary tofollow but the single rule of mixing a given quantity of the compoundwith a given amount of paper stock for certain results.

The compound may be provided in bags or other suitable packages and byits use littlevskill or judgment on' the part of the operator isrequired for producing the desired results in paper manufacture.

What I claim as new and desire to secure by Letters Patent is-- l. Apaper sizing compound, consisting of a mixture of saponified rosin,inert material and a. rosin-soaprdecomposing reagent, in

all the ingredients of the mixture being in dry, ulv'erulent condition,for the purpose set orth.

2. A paper sizing compound, consisting of a mixture of saponified rosin,inert material and a rosin-soap-decomposing reagent more slowly solublethan rosin-soap, in suitable proportions, all the ingredients of the mixture being in dry, pulverulent condition, for the purpose set forth.

3. A paper sizing compound, consisting of a mixture of 'sa'ponifiedrosin, inert material, dehydrated alum or aluminum sulfate, in suitableproportions, the mixture being in dry, dition, for the purpose set orth.

WILLIAM HOSKINS,

In the presence of J. G. ANDERSON, R. A. RAYMOND.

all the ingredients of ulverulent con-

